Aetheryte is the name given to massive shards of crystallized aetheric mist, precisely cut and fused to arcane machinery. While it is not known when or by whom these devices were originally constructed, their teleportational qualities have become the backbone of everyday transportation throughout the realm, with most managed and operated by individual city-states. Their existence in Eorzea seems to be what drew scores of people to settle in the hostile land in the first place.
Though the exact mechanism behind teleportation via aetheryte is still largely a mystery, one theory states that when a sentient being approaches one of the portals, the aether that makes up its body resonates with the aether of the crystals, which in turn results in a complete breakdown of the being's mass, allowing it to temporarily return to the invisible aetheric streams that course throughout the planet.
The being's soul, which cannot be broken down, then guides the particles to a predetermined destination, and upon arrival, the corresponding aetheryte receptacle reconfigures the mist back into its original form. This whole process takes only a matter of moments, allowing for nearly instant transportation to faraway destinations.
However, being broken down to the aetheric level can take its toll on one's body, and rest is often required after several consecutive jumps, especially as the distance becomes greater. As a precaution, most city-states strongly discourage over-teleporting, as it can lead to irreversible damage...
Aetheryte provides the foundation for adventure for all players. It exists out in Field Areas as well as inside cities. Aetheryte serves as a the launching point for a Guildleve and the destination for Teleport and all players are able to use Teleport right from the beginning. In addition, once a quest is complete, an Aethereal Node will appear, allowing players to easily teleport back to the original Aetheryte they came from.